Retaining band for armatures



Aug. 21, 1951 G. P. LESSMANN 2,565,139

RETAINING-BAND FOR ARMATURES Filed Sept. 20, 1949 WITNESSES: Fig. 3. INVENTOR Gerhard P. Lessmonn.

BY W ATTORNEY Patented Aug. 21, 1951 UNITED STATES PATENT OFFICE RETAINING BAND FOR ARMATUBES Application September 20, 1949, Serial No. 116,753

7 Claims.

My invention relates to retaining-bands, and it has more particular relation to the banding of high-speed armatures of direct-current machines, or other dynamo-electric machines.

There are known types of banding, of which the Lynn Patent 2,397,187 is an example, in which the ends of the banding-wire are bent back, in hairpin fashion, alongside of the main body of the banding, and in which the bent-back ends are held to the main body of the banding by means of banding-clips which are laid under the band, and then sent back on top of the band, and soldered together with the banding-wire. It has been found that these banding-clips will open up under the influence of centrifugal force, if the soldered joints are defective in any way. As soon as these banding-clips are bent up in a radial direction, the bent-back end of the interlock wire is also free to move out radially, so that it will eventually open up the hairpin-turn and permit the banding-wire to unravel.

The object of my present invention is to provide a new type of banding-clip means, which will have suflicient strength to prevent its opening up, under the influence of centrifugal force, even though the solder should be melted out or omitted altogether.

An exemplary form of embodiment of my invention is shown in the accompanying drawing, wherein:

Figure l is a fragmentary longitudinal sectional view of a portion of a direct-current dynamoelectric machine, with a conventional or schematic showing of a band, applied on one end of the armature,

Fig. 2 is a developed view of the band, on a somewhat larger scale, showing its manner of construction in accordance with my invention,

Fig. 3 is a crosssectional view on the line III-III in Fig. 2, and

Fig. 4 is an enlarged detail-view showing the manner in which the banding-clip joint is made.

As shown in Fig. 1, my invention is illustrated in application to the armature or rotor-member 3 of a direct-current dynamo-electric machine which has also a field-member or stator-member 4. The invention relates to a banding-wire 5, which is applied, in one or more layers, about the periphery of the coil-ends or end-turns 6 of the armature-winding, to retain the winding against centrifugal force. In accordance with a customary convention, the banding-wire 5 is schematically or diagrammatically shown, not to scale, in Fig. 1, being illustrated as a single layer, in order to avoid confusion of the small scale drawing, although it is to be understood that the band may consist of; two or three layers, or even more. In the particular case illustrated, the band 5 is used to hold the end-turns 5 against a coil-support l, with an insulating spacer 8 inserted between the upper and lower conductors, and with an insulating layer 9 disposed under the band 5.

The manner of applying the band 5 is illustrated in Fig. 2. The band, as illustrated, comprises the banding-wire 5, a plurality of long underlying lower banding-clips i2, and one or more short upper banding-clips I 3. As previously explained, the banding-wire 5 is applied in one or more 5 layers, the particular example illustrated being a 1 three-layer band, as shown in Fig. 3. Each of the layers of the banding-wire 5 has a plurality of turns lying side-by-side around the end-turns 8 or other cylindrical object to be bound. At least one end of the banding-wire has a turned-back end l4, which makes a hairpin loop through another loop l5 of the bandingwire, and which lies against the main body of the banding, as shown in Fig. 2.

The lower banding-clips 12 have intermediate portions I6 which underlie the banding, and endportions I! which are bent up over the top of the banding.

One or more of the upper banding-clips i3 is used at the place or places where the turned-back end or ends I 4 of the banding-wire are to be held or retained alongside of the main body of the banding. These upper banding-clips l3 have an intermediate portion l8 which overlies one or more end-turns of the top layer of the banding wire 5, as shown in Figs. 2 and 3. The inner ends E9 of these upper banding-clips l3 underlie one or more intermediate turns of said top layer of the banding-wire 5. This construction is obtained by laying down said inner ends [9 of the upper banding-clips l3 before said intermediate turns are wound. Then, when the necessary number of intermediate turns have been wound on top of the inner ends IQ of the upper banding-clips I3, the winding-operation is interrupted long enough to bend the remainder of the upper banding-clips l3 up out of the Way, after which the winding is completed, and the intermediate portions l8 are then laid down over the end-turn or turns of the top layer of the banding-wire.

As shown more particularly in Fig. 4, the outer end 2| of each of the upper banding-clips I3 is then bent down vertically, to overlie, or lie snugly against, the side edge of the banding, and the outer end 2! is then bent horizontally, at 2|, to

overlie the end 22 of a lower banding-clip l2, before the latter is bent up around the banding. The outer end 2| of the upper banding-clip i 3 is long enough to extend only about half as far beyond the main body of the banding, as said end 22 of the corresponding lower banding-clip l2. The extending end-portion 22 of this end of the lower banding-clip I2 is then bent up and over, so as to overlie the horizontal portion of the outer end 2! of the upper banding-clip 13, thus providing a triple-layer clip-end, as shown at 23 in Fig. 4.

Finally, the triple-layer clip-end Z3 is bent up or back against the intermediate vertical portion of the outer end 2| of the upper bandingclip l3, as shown in dotted lines in Fig. 4. In making this bend or fold of the triple-layer clipend 23, care must be taken to see to it, when bending, that the clip remains tight. To this end, it is quite desirable that the extreme tip 24 of the folded-back end-extension 22, which overlay the horizontal portion of the outer end 2| of the upper banding clip, before this bending or folding-operation of the triple-layer clip-end was made, should extend back almost to the bend 2! between the vertical and horizontal portions of said outer end 2! of the upper banding-clip it. Thus, when the upward folding or bending.

of the triple-layer clip-end 23 is made, the endtip or edge 2 will press the bend 2i tightly in, against the main body of the banding, thus keep ing the clip tight.

As has been customary, when using other forms of banding-clips, one of these improved banding-clip assemblies is placed near, but not quite at, the extreme end 26 of the backwardly bent hairpin-extension it, and this extreme end 26 is again folded back on the outside of the banding-clip assembly, after the clip has been secured in place, as shown in Fig. 2. In the present instance, such an operation brings the doubled-back end 25 of the banding-wire H against the outside of the folded-back triple layer clip-end 23, so as to help to hold said clipend in place.

In accordance with the previous practice, I preferably solder all of the retaining-band parts together, particularly the clips and the wires, after the winding of the banding-wire has been completed and the clips have been bent into their final positions. As a result of my banding-clip construction, however, there is only a small leverage which the centrifugal force of a banding-clip can have, upon the loops or bends 2i in my upper banding-clips IS, in the completed or vertically up-bent position of my triple-layer clip-ends 23; and this leverage is small enough so that it will not deform the finished bandingclip assembly, even without any soldering.

While I have illustrated and described my invention in a single preferred form of embodiment, I wish it to be understood that various changes may be made, without departing from the essential spirit of my invention, in various details of folding, numbers of turns, numbers of 1ayers, integral and separate parts, and the like. I desire, therefore, that the appended claims shall be accorded the broadest construction consistent with their language.

I claim as my invention:

1. A retaining-band comprising a bandingwire having one or more layers, each layer having a plurality of turns lying side-by-side around an object to be bound, in combination with a plurality of banding-clip means having intermediate portions which underlie the banding and having other portions which overlie the tops and side edges of the banding, at least one of said banding-clip means including a clip-joint at one side edge of the banding, said clip-joint comprising an'upper clip-end which overlies the top of the banding and said side edge of the banding and also overlies a corresponding end-extension of the underlying banding-portion, said upper clip-end being long enough to extend about half as far beyond said side edge of the banding as said end-extension of the underlying band-portion, the portion of said end-extension which extends beyond said upper clip-end being bent to overlie said upper clip-end to provide a triplelayer clip-end, and said triple-layer clip-end being bent back against an intermediate portion of said upper clip-end, keeping said banding-clip means tight.

2. The invention as defined in claim 1, characterized by said one of said banding-clip means having a portion which underlies one or more intermediate turns of the top layer of the banding-wire.

3. A retaining-band comprising a bandingwire having one or more layers, each layer having a plurality of turns lying side-by-side around an object to be bound, at least one end of said wire having a turned-back end lying against the main body of the banding, in combination with a plurality of banding-clip means having intermediate portions which underlie the banding and having other portions which overlie the tops and side edges of the banding, at least one of said banding-clip means including a clip-joint at one side edge of the banding at a point suitable for retaining said turned-back end of the bandingwire, said clip-joint comprising an upper clip-end which overlies the top of the banding and said side edge of the banding and also overlies a corresponding end-extension of the underlying banding-portion, said upper clip-end being long enough to extend about half as far beyond said side edge of the banding as said end-extension of the underlying band-portion, the portion of said end-extension which extends beyond said upper clip-end being bent to overlie said upper clipend to provide a triple-layer clip-end, and said triple-layer clip-end being bent back against an intermediate portion of said upper clip-end, keeping said banding-clip means tight.

4. The invention as defined in claim 3, characterized by at least one of said triple-layer bentback clip-ends being spaced back from the extreme end of said turned-back end of the banding-wire, and said extreme end being again turned back over said triple-layer bent-back clip-end.

5. A retaining-band comprising a banding wire, a plurality of long underlying lower bandingclips, and one or more short upper banding-clips, the banding-wire having one or more layers, each having a plurality of turns lying side-by-side around an object to be bound, said lower bandingclips having intermediate portions which underlie the banding, at least one of said upper bandingclips having an intermediate portion overlying one or more end-turns of the top layer of the banding-wire, the inner end of said upper banding-clip underlying one or more intermediate turns of said top layer of the banding-wire, the outer end of said upper banding-clip overlying the end of a corresponding lower banding-clip and being long enough to extend about half as far beyond the main body of the banding as said end of said corresponding lower banding-clip, the extending end of said end of said lower banding-clip being bent over to overlie said outer end of the upper banding-clip to provide a triplelayer clip-end, and said triple-layer clip-end being bent back against an intermediate portion of said upper banding-clip, keeping said clip tight.

6. A retaining-band comprising a banding-wire, a plurality of long underlying lower bandingclips, and one or more short upper banding-clips, the banding-wire having one or more layers, each having a plurality of turns lying side-by-side around an object to be bound, at least one end of said wire having a turned-back end lying against the main body of the banding, said lower banding-clips having intermediate portions which underlie the banding, at least one of said upper banding-clips having an intermediate portion overlying one or more end-turns of the top layer of the banding-wire at a point suitable for retaining said turned-back end of the banding-wire, the inner end of said upper banding-clip underlying one or more intermediate turns of said top layer of the banding-wire, the outer end of said upper banding-clip overlying the nd of a corresponding lower banding-clip and being long enough to extend about half as far beyond the main body of the banding as said end of said corresponding lower banding-clip, the extending end of said end of said lower banding-clip being bent over to overlie said outer end of the upper banding-clip to provide a triple-layer clip-end, and said triple-layer clip-end being bent back against an intermediate portion of said upper banding-clip, keeping said clip tight.

7. The invention as defined in claim 6, characterized by at least one of said triple-layer bentback clip-ends being spaced back from the extreme end of said turned-back end of the banding-wire, and said extreme end being again turned back over said triple-layer bentbacl-: clip-end.

GERHARD P. LESSMANN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 405,029 Gordon June 11, 1889 621,530 Marshall Mar. 21, 1899 1,263,232 Grinden Apr. 16, 1918 1,631,396 Beegle June 7, 1927 2,336,139 Vogel Dec. 7, 1943 2,397,187 Lynn Mar. 26, 1946 

